The present invention is directed to equipment employed in the precision manufacturing of products. By way of example and not by way of limitation, the large sizes of aircraft assemblies and the high degree of accuracy required in their manufacture present demanding requirements for equipment used in the manufacturing process. Generally, tooling and equipment used in the precision manufacturing of products, such as producing large assemblies like aircraft assemblies, are costly, have long lead times for their delivery and are often of specialized design so that they are inflexible in their application to a production of a variety of products.
Some portable manual and semi-manual machine tools have been developed to perform accurate drilling operations. One example of an aircraft manufacturing machine tool system is the Static Optical Machine Control (SOMaC) system developed by The Boeing Company and described in U.S. Patent Application Publication 2004/0260422 A1 of Dec. 23, 2004, for “Software for Improving the Accuracy of Machines”. Prior art manufacturing systems have been designed for use with a positioning device such as a numerical control (NC) machine tool or a robotic tool and depend upon such underlying positioning devices for location with respect to a work site on a workpiece. Such underlying positioning devices have proven to be less accurate than is desired for precision manufacturing and similar operations in such high precision environments as, by way of example and not by way of limitation, aircraft assembly operations. The underlying positioning devices such as robotic mechanisms have exhibited excessive flexibility so that the requisite stiffness required for precise end-effector location for operations such as drilling or similar operations cannot be achieved reliably or repeatably.
One attempt to solve this problem included the use of a laser with a manually placed positioning device for locating a drilling tool at a worksite with the requisite accuracy. However, the manual placement of the positioning device is slower than is desired for a high speed, yet accurate operation.
There is a need for an apparatus and method for situating an end-effector with respect to a work site on a workpiece that permits high speed, accurate manufacturing operations.
For purposes of this disclosure, the term “end-effector” is intended to refer to an item that effects work with respect to a workpiece. By way of example and not by way of limitation, an end-effector may include a drill, a punch or a similar material-working item. Also for purposes of this disclosure, the term “tooling” is intended to refer to a fixturing device that holds a workpiece.